The May 21, 2009, issue of the Washington Post has an article about a gay rights group in Maine that is challenging the tax-exempt status of a Catholic Diocese due to its support of a referendum to end same-sex marriage. Here is an excerpt from the article:

A gay rights advocacy group claims that the Roman Catholic Diocese of Maine is violating tax rules by helping a referendum campaign that would repeal the state's new same-sex marriage law.

The Empowering Spirits Foundation said its challenge was filed Wednesday at an Internal Revenue Service office in Dallas. The San Diego-based group said the diocese is engaging in political activity by collecting signatures for the referendum, violating IRS rules applying to nonprofits.